1. Field of Invention
Embodiments of the invention generally relate to audio and video processing. More specifically, at least one embodiment relates to processing audio and video signals in topologies maintained by an audio/video/ancillary data subsystem.
2. Discussion of Related Art
The challenges presented to audio and video processing systems, especially those employed in live broadcasts, are substantial. Many applications of audio and video processing systems require high performance and high reliability. In some applications, even a momentary fault can result in an on-air glitch apparent to a large audience of viewers and/or listeners.
Audio and video systems are often provided as a host system and an additional apparatus that processes the audio and video data based on instructions received from the host system. Despite being a distinct piece of hardware, these audio and video processing apparatuses are completely dependent on communication with the host system. For example, a host system can provide data and control signals required for operation of the audio/video processing apparatus. Such an approach results in an architecture that uses resources of the host system (that may be needed for other tasks) and is immediately rendered inoperative if the host system lags or crashes or should communication between the host system and the apparatus be interrupted or cease altogether.
The importance of high reliability results in some audio/video apparatuses being equipped with a mechanical relay that bypasses the audio/video processing apparatus in the event of a loss of power. However, this approach simply couples the input of the audio/video apparatus to the output of the apparatus. The approach does not allow more advanced functionality of the audio/video processing apparatus to be used.